Oil burner



B. GRUNWALD OIL BURNER 2 Sheets-sheer] Filed MaFGh 5. 1925 Dec. 28 1926. .l 1,611,905

B, GRUNWALD OIL BURNER Filed March 1925 2 sheets-sheer www@ Gtkozum Patented Dec. 28', 1926.

UNITED STATES BERNHARD GRUNWALD, OF OMAHA, NBRASKA.

011. BURNER.

` Application mea Maren 3, 1925.- serial'imiassa.

My invention relates to means for burning relatively heavy liquid fuels, such as kerosene, distillate and fuel-oil, and adapted to be used in furnaces originally constructed for burning coal or other solid fuel, whereby to convert the same into oil-burning furnaces. It is the object of my invention to provide a burner which may be readily applied to furnaces of the class above mentioned, and with which heavy liquid fuels may be eiliciently burned without the production of fumes or smoke. A further object of my invention is to provide a burner of this class in which the generator or oil-Vaporizing means are readily accessible so that any deposit `of carbon or other solids may be conveniently removed from time to time as the accumulation thereof may require. @A further object of my invention is to provide in a burner of this class a generator or oilvaporizer positioned externally of the combustion chamber and heated therefrom by conductiony through relatively massive me- .tallic members extended between the gener-y ator and the combustion area.` A further object of my invention is to provide in a burner of this class means by which the supply of air and fuel may be regulated simultaneously so as to automatically maintain substantially constant proportions thereof, and in which the ratio of openings of the main air-passage and fuel-valve may be varied to compensate differences in the draft of furnaces to which the burner may be applied.

In the accompanying drawings Fig. 1 is a longitudinal vertical section on line 1-1 of Fig. 2- of a burner embodying my invention, Fig. 2 'is a front view of the same,.1*`ig. 3 is a transverse section on the line 3-3 of Fig. 1, Fig. 4 is a detail section on the line 1 4 of Fig. 2, and Fig. 5 is a side view of the burner, disposed in operative relation to a furnace of which portions are broken away to expose the inclosed portion of the burner.

In Carrying out my invention according to the illustrated embodiment thereof, l provide a rectangular box-like case or housing 5 which may be of cast metal with rather thick walls, the bottom of the box being flat and extending at a uniform level, the sides being in uniform vertical planes, and the top having two shoulders or offsets therein, the first shoulder 6 being near the front end, and the second shoulder 7 being intermediate the first shoulder and the rear end.. The

housing 5 is open at the front end and atv the u per side between the rear end and the shoul er 7. In applying the burner to a furnace Aof a type such as illustrated in Fig. 5, the grate used fou burning solid fuel is removed from the furnace, and the upper door B, through which the coal or the like is ordinarily supplied, is tightly closed and not used. The lower or ash-pit door C is provided with an opening justlarge enough to receive the portion of the housing 5 behind the shoulder 6, and the housing is mounted upon said door so that the portion behind said shoulder 6 extends into the furnace, Whilethe front portion of the housing projects from the door at a moderate elevation from theI floor or base on which the furnace rests. y

At the front end of the housing 5, and covering approximately the lower half of the opening, is a door 8 which is hinged at its lower portion, so as to be openable by swinging forwardly and downwardly. Latchhooks 9, pivotedatthe sides of the housing, are adapted to engage pins 10 extending laterally from the edges of the door, for holding the door normally in closed position. The inner sides of the housing adjoining the door 8 are rabbeted to formA guideways for the edges of the air-check plate 11, which fits against the inner side of the door 8 as shown in Fig. 1, and is slidable vertically from the lower or fully open position shown in said figure to -a raised position at which the upper edge of the plate engages the top of the housing and theplate thereby closes the front opening thereof above the door 8. At the center of the plate 11 is a vertical arm 12 which extends up through a notch in the front edge of the housing, said arm at its upper end having a fixed rearwardly extending pin 18 which is engaged in a slot at the end of the control-lever 14. At the center of the door 8 an arm 15 is extended upwardly therefrom, saidarm having-at the upper end a head 17 adapted to )fit over the notch in the housing through which the arm 12 passes, whereby to form a guide for said arm when the door is in closed position. 1When the door 8 is opened the plate 11 remains suspended from the control-lever 14, and the plate may be entirely removed from the assembly by merely lifting and moving the same forwardly, to disengagle it from its guideways and to withdraw t e pin 13 from the slot in the control-lever. By the openiso CII

ing of the door 8 and removal of the plate 11, the entire front end of the housing is opened so that the interior thereof is made freely accessible for the inspection, removal, cleaning and replacing of the generator or vaporizing devices contained therein.

The portion of the housing in front of the shoulder 6 incloses the generator-chamber, and in the upper portion of said chamber is removably disposed the generator or oil-pan 18 which is a shallow rectangular receptacle extending transversely of the housing, and having thick walls,`its outer sides being horizontally ribbed and spaced from the sides of the housing,- as shown. Said pan 18 rests upon the upper edges of a pairof thick vertical plates 19 which are disposed removably upon the bottom of the housing, said plates havin at their lower` portions the laterally extencgling foot-lugs 2O adapted to engage the adjacent sides of the housing for maintaining a suitable spacing ,between the plates and said sides. Horizontally ribbed lugs 21 extend down from the pan 18 into the space between the'plates 19, and the position of the pan longitudinally of said plates is gaged by shoulders formed on the upper edges of the 4plates at the rear side ot the pan. The rear portions of the plates 19 extend back into the retort or mixingchamber which is inclosed by the portions of the housing intermediate the shoulders 6 and 7 and the longitudinal position of the plates is fixed bythe placing thereof between the transverse ribs 22 and 23 which are formed integrally-"with the housing and extend from side to side across the bottom-plate thereof.

Said ribs 22 and 23 also serve to form at the bottom of the housing a pan or receptacle for receiving any of the liquid which may overflow from the generator 18 and reach the bottom .of the housing without being vaporized.

.At one side of the housing, and connecting lthrough which the liquid fuel is delivered,

is arranged to germinate above the cup 25 and is positioned centrally thereof, so that normally the liquid will drop through the hole 28 and into the pan 18 without touching the cup or any portion of the housing. If, however, the falling liquid should be slightly diverted laterally, so as not to pass directly through the hole, it will be caught by the cu and flow down the inside thereof through t e hole, finally dripping 0E the lip fected automatically by a slight increase ot.

weight upon a trigger or trip-lever. Such a trigger or trip-lever 30 is indicated in the drawing, anda cup or small bucket 31 is suspended therefrom, the same being positioned to receive liquid from .the drain-pipe 24, whereby a dripping of oil from said drain-pipe, due to overflow of unburned fuel, will operate the trip-leverto close the valve and thus automatically stop the supply of fuel to the burner. `The feed-pipe 27 is also provided with a fuel-regulating valve 32 which, in the structure illustrated, is arranged for manual control. The valve-stein 33 has a hand-wheel 34 fixedly mounted thereon, and to said stem is also atlixed an indicator or pointer 35 and an arm or crank 36. The pointer is movable adjacent to a graduated quadrant 37 which is secured to the valve-casing, and the crank-arm 36 is movable adjacent to a quadrant 38 having` a series' of holes 39 for receiving a pin or screw 40 by which the arm may be connected withthe quadrant in fixed positions ot' adjustment. One end of the control-lever 14 is pivotally connected with the outer end ot the crank-arm 36, andthe valve is so proportioned that in the adjustments thereof from a maximum to a minimum fuel-supply the arm and the attached end ofthe lever are moved between the positions shown, respectively, by full and dotted lines in Fig. 2. The intermediate portion o'f the controllever 14 is slotted as shown, and rests slidably andpivotally upon an adjustably movable i'ulcrum which is supported upon a standard 41 extended up from :the burnerhousing 5. At the upper end of said standard is a slotted head 42, the direction oi' the slot in said head being such that it is parallel with the slot in the lever when the latter is at the position corresponding with the minimum opening of the fuel-valve, as indicated l by the dotted lines in Fig. 2. -The adjustably movable fulcrum is formed-by a bolt 43 which fits slidably in the slot in the head 42, a sleeve or collar 44 being disposed about the portion ofthe bolt which passes through i the slot in the lever 14, and the axial length of the said sleeve being slightly greater than the thickness of the lever. Washers 45 arc disposed uponl the bolt between the head thereof andthe end of the sleeve 44, and be- "f vtween the head 42 of the standard and the nut 46 which is screwed upon the threaded end of the bolt. Referring to Fig. 4 it will be seen that by tightening of the nut the sleeve 44, which forms the actual fulcrum of the lever, may be clamped to the head 42 in any position of adjustment longitudinally of the slot in said head, and the lever-fulcrum thus varied between said limits of adjustment. It will be obvious that as the fulcrum of the lever is varied the ratio of movement between the fuel-valveand air-check plate will be varied accordingly, shortening of the valve-arm of the lever, for example, resulting 1n a greatervmovement of tlie7 check-plate during the same adjusting movement of the valve. It will also be seen that, as the slots in the control-lever and the head 42 are coincident or in longitudinal register when the check-plate is in closed position and the fuel-valve at minimum opening, adjustments ofthe fulcrum will not change the relation of the valve and plate at said minimum-opening position, but the variation of the lever-ratio will result in increasing or decreasing, as the case may be, the area of the air-passage controlled by the plate 1l, when the fuel-valve is at any position other than that of minimum opening. Holes 47 in the upper/front portion of the housing,r are adapted to admit to the generatorchamber sufficient air for maintaining a pilot-flame when the fuel-supply is reduced tou the minimum and the main air-supply shut off by the check-plate 11.

In the normal operation of the described mechanism, after the same has become thoroughly heated and when there is an adequate supply of fuel and air, the mixing of the fuel-vapor with a proper pro ortion of air for combustion thereof occurs uring the passage f the -gaseous materials rearwardly from the generator-chamber through the retort or mixing chamber, and the combustion of the fuel commences near the rearward end of said chamber, continuing out into the open-topped 4fire-pan or rearward portion of the housing. lVhen properly regulated, a clean white flame rises from the lire-pan into the combustion-chamber of the furnace, substantially as indicated in Fig. 5, the flame being directed so as not to strike the furnacewalls and` deposit soot thereon. The heat from the combustion zone is conducted by the thick walls of the burner-housing to theoutei` end thereof about the generator-chamber, and the plates 19 servel to conduct heat directly to the generator or oil-pan 18 for keeping the same at the required temperature for vaporizing the liquid fuel. The air and oil-vapors while passing rearwardly through the mixing-chamber or retort are heated by radiation from the plates 19 and the walls of the housing, the radiation being increased by reason of the longitudinal ribs or corrugations 48 on the vertical inner sides of the housing. When the supply of fuel is reduced by partial closing of the fuelvalve, the air-supply is correspondingly reduced by the raising of the air-check plate 11, the rate of flow of the air and oil-vapor through the housing is' thus reduced` and by reason of thereduced rate of flow the conibustion commences at 'a point nearer to the front of the housing. When the supply ot' the liquid fuel is reduced to a minimum, and the air-supply accordingly limited to that which enters the housing through the holes 47 and 28, the draft through the housing becomes so reduced that combustion of the limited supply of fuel takes place directly at the pan 18, which is thus kept heated suiiiciently to continue the vaporization of the liquid, and thereby to maintain a pilotfiame about the marginal portions of the pan. lVhen the fuel-supply is increased, after operating for a time at the minimum rate` there may be at first a slight overflowing of the pan 18, whereby. the oil will pass down over the ribbed outer surfaces of the pan and its depending lugs 21 in a thin vsheet or film, the oil being thus subject to rapid heating and vaporization, sol that a large flame is quickly produced. Atthe same time the greater air-draft resulting from the opening of the air-check 11 sweeps the increasing xolume of oil vapors rearwardly through the housing, so that the point at which combustion commences will be nearer to the rear end of the housing` and the heating of the generator again effected by conduction through the plates 19 and the housing-walls. In starting the 'operation of the burner, the pan 18 may be initially heated by placing" therein a small quantity of volatile liquid lfuel land igniting the same, or if the regular fuel is not too heavy a small charge thereof may be run intothe pan, ignited, and burned for a suflicient time to heat the same to generating' temperature before starting vthe continuous supply of fuel thereto. Starting of the burner may also be effected by entirely removing the pan 18 from the housing, heating the pan by any desired` external means,y

then replacing the same in the burner, starting the fuel supply, and igniting the vapors produced when the liquid fuel begins to flow into the heated pan. The removal of the pan is readily eifected after opening the door Sand lifting out the plate 1l, as hereinbefore explained. Substantially the sainel procedure may be employed when it is desired to remove fromthe pan any. accumulation of solids therein such as result from the use of heavy fuels which have non-volatile residues. llf the cleaning of the pan is effected with reasonable rapidity, it may be taken out of the housing, cleaned, and re-.

operation of the burner may be immediately resumed, without re-generating.

It will be particularly noted that the automatic and simultaneous variation of the fuel and air supply to the burner, effected by the control-lever 14, insures a correct and economical combustion of' the fuel at all rates of operation .of the burner, by so proportioning the supply of fuel and air that for any rate of fuel-feed there will be neither a deficiency of air for complete combustion, nor an excess of air tending to reduce the temperature of the combustion products. By adjustments of' the movable fulcrum of the control-lever, the operation of said lever may be so regulated as to readily compensate for differences of draft in various furnaces to which the burner may be applied, and after the draft-adjustment has been made, the fuel and air will be properly proportioned for all rates of fuel-feed.

Now, having described my invention, what I claim and desire to secure by Letters Patent is:

l. An oil burner,.comprising a housing having an open-topped rear portion forming a fire-pan and extending into the combustion chamber of a furnace, the front portion of said housing inclosing a generator-chamber and extending externally of the furnace, and the intermediate portion of the housing inclosing a mixing-chamber connecting the generator-chamber and the fire-pan, heatconductive members extending longitudinally of the mixing-chamber and into the generator-chamber, a generator supported upon said heat-conductive members in spaced relation to the walls of said chamber, means for supplying liquid fuel to said generator, and means for controlling admission of air to said chamber,

2. An oil burner, comprising a thickwalled heat-conductive housing having a generator-chamber at the front portion thereof and said portion arranged externally of a furnace, said housing having an open rear portion extending into the heating chamber of the furnace, and the intermediate portion lof the housing inclosing a mixing-chamber communicating with the open rear portion and with the generatorchamber, heat-conductive plates removably disposed within and extending longitudinally of the mixing-chamber and into the generator-chamber, a generator comprising a shallow receptacle for liquid fuel supported removably upon said plates Within and spaced from the Walls of said generatorchamber, a door partially closing the end of the housing adjoining said chamber, and a draft-controlling plate normally guided by said door and movable to positions for restricting the opening past the door, said plate being removable from the housing when said door is opened, whereby to afford free access through said opening to the generator-chamber.

3. An oil burner, comprising a horizontally disposed housing having an open rear portion extending into the heating chamber of a furnace, the front portion of said housing inclosing a generator-chamber and extending externally of the furnace, a shallow thick-walled oil-pan having horizontally ribbed outer surfaces and disposed in said generator-chamber in spaced relation to the walls thereof, heat-conductive members supporting said oil-pan and extendin therefrom through the housing into proximity to the open'rear portion thereof, a feed-pipe for liquid fuel, said pipe terminating outside the housing above said oil-pan and arranged to deliver the fuel to said pan through an opening in the top of the housing, a Valve for controlling the flow of liquid through said pipe, draft-controlling means movable to regulate admission of air .to thegeneratorchamber, and means connecting said fuel-valve and draft-controlling means to coordinate adjustments thereof.

4. In an oil burner, a housing inclosing a generator chamber inthe front portion thereof and having a passage of reduced sectional area extending rearwardly from said chamberand communicating with an open fire-pan, said rear portion of the housing extending into the heating chamber of a furnace and the 'front portion projecting externally of the furnace, an oil-pan disposed in said generator-chamber, heat-conductiveJ members extending from said oil-pan through the passage toward the rear portion of the housing, the housing having an opening therein above the oil-pan, a feedpipe for liquid fuel, said pipe terminating above said opening in the housing, 'a cup formed on the top .of the housing aboutsaid opening, and an annular lip formed about said opening at the inner end thereof. for the purpose described.

BERNHARD GRUNWALD. 

